900 research outputs found
The B -- TAU FCNC connection in SUSY Unified Theories
In the context of SUSY grand unification a link is established between the
hadronic and leptonic soft breaking sectors. Such relation is here exploited in
particular for FCNC processes in B physics. It is shown how bounds on leptonic
FCNC involving the third generation translate into constraints on FC B decays.
In the second part of the contribution we show that tests of lepton
universality in K and B decays can represent an interesting handle to obtain
relevant information on the amount of FCNC in the second and third fermion
generation.Comment: 9 pages, 4 figures. Based on talks given at: DIF06, International
Workshop on discoveries in flavour physics at e+e- colloders, Laboratori
Nazionali di Frascati (Italy), February 28- March 03, 2006; XLIst Rencontres
de Moriond, La Thuile, 5-11 March 2006; CORFU2005, Corfu Summer Institute on
EPP, Corfu, Greece, September 4-26, 200
The challenge of brain complexity: A brief discussion about a fractal intermittency-based approach
In the last years, the complexity paradigm is gaining momentum in many research fields where large multidimensional datasets are made available by the advancements in instrumental technology. A complex system is a multi-component system with a large number of units characterized by cooperative behavior and, consequently, emergence of well-defined self-organized structures, such as communities in a complex network. The self-organizing behavior of the brain neural network is probably the most important prototype of complexity and is studied by means of physiological signals such as the ElectroEncephaloGram (EEG). Physiological signals are typically intermittent, i.e., display non-smooth rapid variations or crucial events (e.g., cusps or abrupt jumps) that occur randomly in time, or whose frequency changes randomly. In this work, we introduce a complexity-based approach to the analysis and modeling of physiological data that is focused on the characterization of intermittent events. Recent findings about self-similar or fractal intermittency in human EEG are reviewed. The definition of brain event is a crucial aspect of this approach that is discussed in the last part of the paper, where we also propose and discuss a first version of a general-purpose event detection algorithm for EEG signal
Constraints on SUSY Lepton Flavour Violation by rare processes
We study the constraints on flavour violating terms in low energy SUSY coming
from several processes as li -> lj gamma, li -> lj lj lj and mu -> e in Nuclei.
We show that a combined analysis of the processes allows us to extract
additional information with respect to an individual analysis of all the
processes. In particular, it makes possible to put bounds on sectors previously
unconstrained by li -> lj gamma. We perform the analysis both in the mass
eigenstate and in the mass insertion approximations clarifying the limit of
applicability of these approximations.Comment: 23 pages, 15 figures. Typos corrected, several references and
equations added. Results and conclusions completely unchanged. Accepted
version for publication in JHE
Climate change assessment for Mediterranean agricultural areas by statistical downscaling
In this paper we produce projections of seasonal precipitation for four Mediterranean areas: Apulia region (Italy), Ebro river basin (Spain), Po valley (Italy) and Antalya province (Turkey). We performed the statistical downscaling using Canonical Correlation Analysis (CCA) in two versions: in one case Principal Component Analysis (PCA) filter is applied only to predictor and in the other to both predictor and predictand. After performing a validation test, CCA after PCA filter on both predictor and predictand has been chosen. Sea level pressure (SLP) is used as predictor. Downscaling has been carried out for the scenarios A2 and B2 on the basis of three GCM's: the CCCma-GCM2, the Csiro-MK2 and HadCM3. Three consecutive 30-year periods have been considered. For Summer precipitation in Apulia region we also use the 500 hPa temperature (T500) as predictor, obtaining comparable results. Results show different climate change signals in the four areas and confirm the need of an analysis that is capable of resolving internal differences within the Mediterranean region. The most robust signal is the reduction of Summer precipitation in the Ebro river basin. Other significative results are the increase of precipitation over Apulia in Summer, the reduction over the Po-valley in Spring and Autumn and the increase over the Antalya province in Summer and Autumn
Enantio-Complementary Continuous-Flow Synthesis of 2-Aminobutane Using Covalently Immobilized Transaminases
Chiral amines are a common feature of many active
pharmaceutical ingredients. The synthesis of very small chiral
amines is particularly challenging, even via biocatalytic routes, as the
level of discrimination between similarly sized R-groups must be
exceptional, yet their synthesis creates attractive building blocks that
may then be used to prepare diverse compounds in further steps.
Herein, the synthesis of one of the smallest chiral amines, 2-
aminobutane, using transaminases, is being investigated. After
screening a panel of mainly wild-type transaminases, two candidates
were identified: an (S)-selective transaminase from Halomonas
elongata (HEwT) and a precommercial (R)-selective transaminase
from Johnson Matthey (*RTA-X43). Notably, a single strategic
point mutation enhanced the enantioselectivity of HEwT from 45
to >99.5% ee. By covalently immobilizing these candidates, both enantiomers of 2-aminobutane were synthesized on a multigram scale, and the feasibility of isolation by distillation without the need for any solvents other than water was demonstrated. The atom economy of the process was calculated to be 56% and the E-factors (including waste generated during enzyme expression and immobilization) were 55 and 48 for the synthesis of (R)-2-aminobutane and (S)-2-aminobutane, respectively
"Flavored" Electric Dipole Moments in Supersymmetric Theories
The Standard Model (SM) predictions for the hadronic electric dipole moments
(EDMs) are well far from the present experimental resolutions, thus, the EDMs
represent very clean probes of New Physics (NP) effects. Especially, within an
MSSM framework with flavor-changing (but not necessarily CP violating) soft
terms, large and potentially visible effects to the EDMs are typically
expected. In this Letter we point out that, beyond-leading-order (BLO) effects,
so far neglected in the literature, dominate over the leading-order (LO)
effects in large regions of the parameter space, hence, their inclusion in the
evaluation of the hadronic EDMs is unavoidable.Comment: 4 pages, 1 figur
Atmospheric Pressure Non-thermal Plasma for Air Purification: Ions and Ionic Reactions Induced by dc+ Corona Discharges in Air Contaminated with Acetone and Methanol
Atmospheric pressure mass spectrometry (APCI-MS) was used to investigate the positive ions in air containing acetone (A), methanol (M) and mixtures thereof (A + M), subjected to +dc corona discharges. The results of experiments with isotopically labelled analogues, perdeuterated acetone Adeu and methanol Mdeu, and relevant thermochemical data found in the literature allowed us to identify the main ionic reactions occurring in single component systems (A or M) and in binary mixtures (A + M). It is concluded that, thanks to its significantly higher proton affinity, A is very efficient in quenching M-derived ions at atmospheric pressure. These conclusions provide a rationale for interpreting the results of a parallel investigation on the reciprocal effects of M and A when treated together in air at atmospheric pressure with +dc corona in a non-thermal plasma reactor developed previously in our laboratory. Specifically, we observed a marked drop in the degradation efficiency of methanol when it was treated in the presence of an equivalent amount of acetone. This effect is attributed to acetone interfering with ion-initiated degradation processes of methanol, and supports the conclusion\ua0that ions and ionic reactions are important in dc+ corona induced oxidation of volatile organic pollutants in air
Higgs-Mediated tau --> mu and tau --> e transitions in II Higgs doublet Model and Supersymmetry
We study the phenomenology of the mu-tau and e-tau lepton flavour violation
(LFV) in a general two Higgs Doublet Model (2HDM) including the supersymmetric
case. We consider several LFV decay modes of the charged fermion tau, namely
tau-> l_jgamma, tau->l_j l_k l_k and tau-> l_jeta. The predictions and the
correlations among the rates of the above processes are computed. In
particular, it is shown that tau->l_jgamma processes are the most sensitive
channels to Higgs-mediated LFV specially if the splitting among the neutral
Higgs bosons masses is not below the 10% level.Comment: v2=published version: 13 pages, 4 figures, text improved and
reference added. Two loop effects (relevant for tau->l_jgamma) added.
Conclusions unchange
Oxidation of clofibric acid in aqueous solution using a non-thermal plasma discharge or gamma radiation
In this work, we study degradation of clofibric acid (CFA) in aqueous
solution using either ionizing radiation from a Co source or a
non-thermal plasma produced by discharges in the air above the solution. The
results obtained with the two technologies are compared in terms of
effectiveness of CFA degradation and its by-products. In both cases the CFA
degradation follows a quasi-exponential decay in time well modelled by a
kinetic scheme which considers the competition between CFA and all reaction
intermediates for the reactive species generated in solution as well as the
amount of the end product formed. A new degradation law is deduced to explain
the results. Although the end-product CO was detected and the CFA
conversion found to be very high under the studied conditions, HPLC analysis
reveals several degradation intermediates still bearing the aromatic ring with
the chlorine substituent. The extent of mineralization is rather limited. The
energy yield is found to be higher in the gamma radiation experiments.Comment: 25 pages, 7 figure
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